Self-gauging and readily removable cutter bit



OCt- 6, c BRQWN ETALv SELF-GAUGING AND READILY REMOVABLE CUTTER BITFiled Dec. 20, 1955 3 Sheets-Sheet l INVENTORS Clarence H. Brown BYRobert A. McCallurr ATTORNEY Oct. 6, 1959 c. H. BROWN ETAL 2,907,559

SELF-GAUGING AND READILY REMOVABLE CUTTER BIT Filed Dec. 20, 1955 :sSheets-Sheet 2 F 18 4, i INVENTORS Clarence H Brown BY Robert A. McCallum W qfi eww m ATTORNEY O t- 6, 1 c. H. BROWN ETAL ,9

k SELF-GAUGING AND RE IADILY REMOVABLE CUTTERBIT Filed Dec. 20, 1955 5Sheets-Sheet 3 IN V EN TORS Clarence H. Brown BY Robert I-\.Mc Callumyew 4. M

A TTORNE) United States Patent SELF-GAUGING AND READILY RnMovAnLn CUTTERBIT Clarence H. Brown, Chicago, and Robert A. McCallum,

Clarendon Hills, 111., assignors to Goodman Manufacturing Company,Chicago, Ill., a corporation of Illinois Application December 20, 1955,Serial No. '554,249 2 Claims. (Cl. 26233) This invention relates toimprovements in cutter bit carrying chains, and more particularlyrelates to such cutter bit carrying chains as are adapted for continuousmining machines.

A principal object of the invention is to provide a novel and improvedform of cutter bit carrying chain arranged with a view towardsimplicity, ruggedness and efficiency in construction and operation.

A still further object of the invention is to provide a cutter chain andcutter bit therefor so arranged as to eliminate the usual set screws tohold the bit in position in the chain and to take the reaction ofcutting against the back side of the socket for the bit.

Still another object of the invention is to provide a cutter chainhaving a bit carrying socket therein with a simplified form of holdingmeans at the back side of the socket enabling the bits to be insertedand removed from the chain without the use of the usual wrenchesrequired for this purpose.

Still another object of the invention is to provide a novel and improvedform of cutter bit having a hardened cutting surface and so formed as toenable the bit to be self-gauging and readily inserted or removed fromits socket in the cutter chain.

Still another object of the invention is to provide a cutter chain blockand bit in which the bit and socket are arranged to cooperate with eachother to gauge the bit Without the use of the usual tools and tomaintain the bit in position in the chain by a spring pressed detentarrangement, positively holding the bit to the block when once insertedin the socket and enabling ready removal thereof.

These and other objects of the invention will appear from time to timeas the following specification proceeds and with reference to theaccompanying drawings wherein:

Figure l is a fragmentary perspective View of a cutter chain and barwith the bar shown in transverse section;

Figure 2 is a transverse sectional view taken substantially along lineII-II of Figure 1;

Figure 3 is an enlarged fragmentary View of the cutter chain with partsof the cutter chain block broken away and shown in section;

Figure 4 is an enlarged fragmentary sectional View of the cutter chainblock showing the cutter bit in the proc ess of being inserted in theblock;

' Figure 5 is a fragmentary plan view of the cutter chain and its bits;and

- Figure 6 is a'perspective View of the cutter chain bit looking at thebit from the rear end portion thereof.

In the embodiment of the invention illustrated in the drawings,reference character 10 designates generally a cutter bar having acontinuous cutter chain 11 guided for movement therealong and detachablycarrying cutter bits 27. The cutter bar 10 may be a horizontal cutterbar, such as, is used in a continuous mining machine of the rotaryboring type (not shown). Such bars are usually positioned at the top andbottom of the machine and guide a continuous cutter chain to cut out thespace left between the boring bars of the machine, to provide a cleanroof and bottom. The links of the cutter chain are shown as pivotingabout axes parallel to the plane of travel of the chain about the cutterbar to accommo date the chain to face the coal face and turn about idlersprockets (not shown) at each end of the cutterbar.

:While the chain is herein shown as being of the type in which the linksare connected together for pivotal movement about axes parallel to theplane of travel of the chain along the cutter bar, it should beunderstood that the chain may pivot about axes perpendicular to theplane of travel along the cutter bar, if desired, where it is requiredthat the chain cut horizontal or vertical kerfs in a mine wall andtravel along each side and around the end of the cutter bar.

The cutter bar 10 is shown as having a channeled guide 12 extendingtherealong and opening to the outside of the bar and forming a guidealong which the cutter chain slidably moves. The cutter chain guide, 11is shown as being of a reduced cross-section adjacent its inner end, toreceive and guide an inner end portion 13 of a block 15 of the cutterchain. As herein shown, the block 15 has a link portion 16 extendingtherefrom intermediate the ends thereof and Wider than the inner endportion 13 of the block 15. The link portion 16 has opposite bevelededges 17, the inner edges of which ride along outwardly beveled edges 19of the guide 12, and the opposite edges of which ride along innerbeveled edges 20 of liners 21 for the outer end portions of thechanneled guide 12. t

The link portion 16 of one block is shown in Figure 3 as extendingwithin a recess or slot 30 in the next adjacent block and as beingpivotally connected to said block as by a pivot pin 31, the axis ofwhich is parallel to the plane of travel of the cutter chain along thecut ter bar. The pivot pin 31 is shown as being carried in a hole 32drilled from the inner end of the cutter chain block. A pin 33 isprovided to secure the pin 31 to its respective block. A hole 34 of alesser diameter than the hole 32, forms a continuation of the hole 32and opens to the outer side of theblock, to afford access to the pin 31,to enable the pin 31 to be readily driven from the block, when it isdesired to dismantle the chain.

Each cutter block 15 is provided with a bit carrying socket 37 for acutter bit 27. In Figures 3, 4 and 5 we have shown the socket 37 asbeing for a center bit 27 and as being formed within the block 15 toextend perpendicular to the face of the block and position the'bit toout along the center of the kerf. The bits of the next succeeding blocksmay be positioned to the right or left of center as shown in Figure 2,to provide a cutting pattern to completely cut out the kerf and to avoidthe leaving of an uncut core within the kerf. The extreme right and leftor top and bottom bits are shown as being positioned to extend parallelto the faces 25 of the liners 21.

Each socket 37 may be drilled within the block from the outer endthereof and may be of a slightly larger diameter than the diameter of ashank 39 of the cutter bit 27. A cross drilled hole 40 intersects thebottom of the socket 37 to accommodate cleaning thereof. A slot 41extends from the socket 37 toward the forward end of the block from aposition disposed intermediate the ends of said socket. The slot 41 hasan inclined face 43 cooperating with a gauging face 44 on the undersideof a forwardly projecting keying portion 45 of the cutter chain bit 27.The inclined gauging face 44 of the cutter chain bit 27 gauges acuttingface 47 of the bit with respect to the block 15, and also cams the backof the shank 39 of the bit against the back of the socket. 37, to

resist the cutting loads against the back of the shank and socket. Thekeying portion 45 maintains the bit in centered relation with respect toits respective cutter chain block 15.

A bit holder 35 is shown as being carried Within a socket 49intersecting the hole 34 and extending longitudinally of the block 15and opening into the socket 37. The bit holder 35 includes generally acylindrical cage or seating member 50 for a spring 51, seated adjacentits outer end onan inwardly extending flange 53 of said cage.

The spring 51 encircles a stem 54 of a detent 55 and abuts a shoulderedportion 56 of the head of the detent to bias thedetent within the socket37. The cage 50 abuts a shouldered portion 59 of the socket 49 at itsinner end and is maintained in position within the socket 49 by asuitable retaining means such as a roll pin otl, removaoly mounted inthe block 15 and extending across the rear end portion of said socket49. The roll pin 60 also extends within a recessed portion 61 .of thestem 54 of the detent 55 and is adapted to abut an outer or rear face 63of said recessed portion, to limit inward movement of the detent 55within the socket 37. g

The detent 55 has a generally conical engaging face 65 engageable withina generally V-shaped recess 66 formed in the back of the shank 39 of thecutter bit 27, to retain said cutter bit within the socket 37. The shank39 has a rear beveled face 67 extending from the bottom thereof andengageable with the conical face of the detent 55 when the cutter chainbit 27 is forced within the socket 37, to depress the detent 55 andaccommodate the bit to be forced within the socket 37 and then releasethe detent to follow theinclined face of the recess 66 and detachablyhold the bit 27 within block -15.

The keying portion 45 of each cutter chain bit 27 is shown asterminating into transverse inclined faces 68 inclined outwardly withrespect to the shank in the direction of cutting and merging into theshank 39. The faces 68 are also inclined to converge inwardly toparallel faces 69 defining the lower portion of a heel 70 of a reducedcross-sectionalarea from the cross-sectional area of the keying portion45 of the bit. The heel 70 has a recess 71 formed in the forward endthereof for a hardened cutting insert 73, the forward face of whichforms the cutting face 47.

The detent 55 thus tilts the inner end portion of the shank toward theforward ,end of the socket about the inclined bottom wall or gaging face44 of the keying projection 45. The gaging face 44 thus cams the bit totake the cutting loads off of the detent and apply the cutting loads atthe back outer end portion and front lower end portion of the shank andsocket.

The insert 73 may be made from one of the alloys containing cobalt,chromium, tungsten and molybdenum such as stellite, or may be any otherhard metal capable of taking the heavy cutting loads encountered in thecon- .in the direction of travel of the bit and said insert and the heel70 areshown as being inclined inwardly from the uppermargins of theparallel faces 69 and as being tapered from the forward to rear endthereof to provide clearance for the bit during cutting. The heel 70extends ,rearwardly of the shank 39 and terminates at its lower or innerend in spaced relation with respect to the outer surface of the block 15when the bit is in position in the block, and forms a shoulder 75 tofacilitate the insertion of a pry bar between the block 15 and saidshoulder, to accommodate ready removal of the bit from the block. Theouter surface of the heel 70 is relatively flat, being inclineddownwardly from the cutting face of theinsert'73 toward the rear end ofthe bit and providing a flat surface capable of being struck by ahammer,

hold the bit in place in said socket.

It may be seen from the foregoing that a rugged simple and eflicientcutter bit has been provided which is self-gauging and that the inclinedgauging face thereof not only gauges the bit to the correct cuttingdepth, but also earns the back of the shank of the bit against the backof the socket to resist the loads encountered during cutting andrelieves the detent 55 from the cutting loads, enabling said detent toserve only as a means for retaining the bit within its socket.

It may further be seen that the bit is so arranged as to be readilyinserted or removed from its socket without the use of the usualwrenches, thus avoiding the troubles incurred with the freezing of theset screws heretofore used, and making it unnecessary to tap the socketor hole for the set screw, and simplifying the insertion and removal ofthe bit from its block.

While we have herein shown and described one form in which our inventionmay be embodied, it should be understood that various modifications andvariations of our invention may be effected without departing from thespirit and scope of the novel concepts thereof.

We claim as our invention:

1. In a cutter chain, a cutter bit, a cutter block form ing a mountingfor said bit, a self-centering gauging retaining connection between saidblock and bit retaining said bit to said block by driving said bitwithin said block including a socket in said block opening to an outerface thereof and having a slot extending forwardly from said sockethaving centering side walls and a gauging face inclined outwardly fromsaid socket and facing toward the outside of said socket, said cutterbit having a cutter portion and a shank portion extending therefrominsertable within said socket, said shank portion having a keyingprojection projecting forwardly therefrom for registry with said slotand having generally parallel centering walls cooperating with the wallsof said slot and a gauging and camming face connecting said wallstogether and inclined outwardly from said shank portion for cooperationwith said inclined face of said slot and gauging the bit to the propercutting depth, and means forretaining said cutter bit in said socketcomprising detent bit retaining means held in said block and biased tointersect said socket through the trailing wall thereof, a recessedportion onthe trailing side of said shank portion adapted to be engagedby said detent retaining means upon the driving of said cutter bitwithin said socket, said shank portion being of a lesser cross-sectionalarea than the cross-sectional area of said socket and said gauging andcamming face camming said bit to take the cutting loads at the back ofsaid shank and socket and off of said detent retaining means, wherebysaid detent retaining means serves only to retain said cutter bit withinits socket and accommodates removal of said bit from said socket byprying. I

2. In a cutter chain, a cutter block having a socket therein opening tothe outer face thereof and having a slot extending from said sockettoward the forward end of said block having generally parallel sidewalls and an inclined gauging face connecting said side Walls together,inclined forwardly of said socket and facing toward the outside of saidsocket and block, a cutter bit for insertion within said socket having acutter portion and having a shank portion extending inwardly from saidcutter portion for insertion within said socket and of a lessercross-sectional area than the cross-sectional area of said socket, saidshank having a vrecess on the trailing side thereof, a detent memberbiased to engage said recess -to retain said shank within said socket,said shank having a keying projection projecting forward therefrom forregistry with said slot and having generally parallel side walls and aninclined bottom wall in- References Cited in the file of this patentUNITED STATES PATENTS Meutsch May 9, 1933 Bowman Jan. 13, 1948 MorrowSept. 27, 1949 Fulke July 24, 1951 Cartlidge Oct. 11, 1955 Bruestle Oct.9, 1956 FOREIGN PATENTS Germany May 21, 1932 Great Britain May 25, 1933

